32feet/Samples/NfcReaderApp/NfcReaderApp.Android/MainActivity.cs

using System;

using Android.App;
using Android.Content.PM;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
using Android.Content;
using Android.Nfc;

namespace NfcReaderApp.Droid
{
    [Activity(Label = "NfcReaderApp", Icon = "@mipmap/icon", Theme = "@style/MainTheme", MainLauncher = true, ConfigurationChanges = ConfigChanges.ScreenSize | ConfigChanges.Orientation | ConfigChanges.UiMode | ConfigChanges.ScreenLayout | ConfigChanges.SmallestScreenSize )]
    public class MainActivity : global::Xamarin.Forms.Platform.Android.FormsAppCompatActivity
    {
        protected override void OnCreate(Bundle savedInstanceState)
        {
            TabLayoutResource = Resource.Layout.Tabbar;
            ToolbarResource = Resource.Layout.Toolbar;

            base.OnCreate(savedInstanceState);

            Xamarin.Essentials.Platform.Init(this, savedInstanceState);
            global::Xamarin.Forms.Forms.Init(this, savedInstanceState);

            LoadApplication(new App());
        }

        protected override void OnNewIntent(Intent intent)
        {
            if(intent.Action == Android.Nfc.NfcAdapter.ActionNdefDiscovered)
            {
                var messages = intent.GetParcelableArrayExtra(Android.Nfc.NfcAdapter.ExtraNdefMessages);
                NdefMessage msg = (NdefMessage)messages[0];

            }
            base.OnNewIntent(intent);
        }
        public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Android.Content.PM.Permission[] grantResults)
        {
            Xamarin.Essentials.Platform.OnRequestPermissionsResult(requestCode, permissions, grantResults);

            base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }
}